using System.Collections.Generic;
using Articy.Unity;
using Articy.Unity.Interfaces;
using Articy.Unity.Utils;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;

[RequireComponent(typeof(ArticyFlowPlayer))]
public class ArticyDebugFlowPlayer : MonoBehaviour, IArticyFlowPlayerCallbacks
{
	[Header("UI")]
	// a prefab used to instantiate a branch
	public GameObject branchPrefab;
	// the display name label, used to show the name of the current paused on node
	public Text displayNameLabel;
	// the main text label, used to show the text of the current paused on node
	public Text textLabel;

	// our 3 info labels in the middle of the panel, displaying basic information about the current pause.
	public Text typeLabel;
	public Text technicalNameLabel;
	public Text idLabel;

	// the ui target for our vertical list of branch buttons
	public RectTransform branchLayoutPanel;

	// the preview image ui element. A simple 64x64 image that will show the articy preview image or speaker, depending on the current pause.
	public Image previewImagePanel;

	[Header("Options")]
	// you can set this to true to see false branches in red, very helpful for debugging.
	public bool showFalseBranches = false;
	
	// the flow player component found on this game object
	private ArticyFlowPlayer flowPlayer;

	// Used to initializes our debug flow player handler.
	void Start()
	{
		// you could assign this via the inspector but this works equally well for our purpose.
		flowPlayer = GetComponent<ArticyFlowPlayer>();
		Debug.Assert(flowPlayer != null, "ArticyDebugFlowPlayer needs the ArticyFlowPlayer component!.");

		// by clearing at start we can safely have a prefab instantiated in the editor for our convenience and automatically get rid of it when we play.
		ClearAllBranches();

		// just a little reminder text to actually set a start on object, otherwise the Flowplayer won't do anything and just idles.
		if (flowPlayer != null && flowPlayer.StartOn == null)
			textLabel.text = "<color=green>No object selected in the flow player. Navigate to the ArticyflowPlayer and choose a StartOn node.</color>";
	}

	// This is called everytime the flow player reaches and object of interest.
	public void OnFlowPlayerPaused(IFlowObject aObject)
	{
		if(aObject != null)
		{
			typeLabel.text = aObject.GetType().Name;

			// reset, just in case we don't have any
			idLabel.text = string.Empty;
			technicalNameLabel.text = string.Empty;

			var articyObj = aObject as IArticyObject;
			if(articyObj != null)
			{
				idLabel.text = articyObj.Id.ToHex();
				technicalNameLabel.text = articyObj.TechnicalName;
			}
		}
		// To show the displayname in the ui of the current node
		var modelWithDisplayName = aObject as IObjectWithDisplayName;
		if (modelWithDisplayName != null)
			displayNameLabel.text = modelWithDisplayName.DisplayName;
		else
			displayNameLabel.text = string.Empty;

		// To show text in the ui of the current node
		// we just check if it has a text property by using the object property interfaces, if it has the property we use it to show the text in our main text label.
		var modelWithText = aObject as IObjectWithText;
		if (modelWithText != null)
			textLabel.text = modelWithText.Text;
		else
			textLabel.text = string.Empty;

		// this will make sure that we find a proper preview image to show in our ui.
		ExtractCurrentPausePreviewImage(aObject);
	}

	// called everytime the flow player encounteres multiple branches, or paused on a node and want to tell us how to continue.
	public void OnBranchesUpdated(IList<Branch> aBranches)
	{
		// we clear all old branch buttons
		ClearAllBranches();

		// for every branch provided by the flow player, we will create a button in our vertical list
		foreach (var branch in aBranches)
		{
			// if the branch is invalid, because a script evaluated to false, we don't create a button, unless we want to see false branches.
			if (!branch.IsValid && !showFalseBranches) continue;

			// we create a our button prefab and parent it to our vertical list
			var btn = Instantiate(branchPrefab);
			var rect = btn.GetComponent<RectTransform>();
			rect.SetParent(branchLayoutPanel, false);

			// here we make sure to get the Branch component from our button, either by referencing an already existing one, or by adding it.
			var branchBtn = btn.GetComponent<ArticyDebugBranch>();
			if(branchBtn == null)
				branchBtn = btn.AddComponent<ArticyDebugBranch>();

			// this will assign the flowplayer and branch and will create a proper label for the button.
			branchBtn.AssignBranch(flowPlayer, branch);
		}
	}

	// convenience method to clear everything underneath our branch layout panel, this should only be our dynamically created branch buttons.
	private void ClearAllBranches()
	{
		foreach (Transform child in branchLayoutPanel)
			Destroy(child.gameObject);
	}

	// method to find a preview image to show in the ui.
	private void ExtractCurrentPausePreviewImage(IFlowObject aObject)
	{
		IAsset articyAsset = null;

		previewImagePanel.sprite = null;

		// to figure out which asset we could show in our preview, we first try to see if it is an object with a speaker
		var dlgSpeaker = aObject as IObjectWithSpeaker;
		if (dlgSpeaker != null)
		{
			// if we have a speaker, we extract it, because now we have to check if it has a preview image.
			ArticyObject speaker = dlgSpeaker.Speaker;
			if (speaker != null)
			{
				var speakerWithPreviewImage = speaker as IObjectWithPreviewImage;
				if (speakerWithPreviewImage != null)
				{
					// our speaker has the property for preview image and we assign it to our asset.
					articyAsset = speakerWithPreviewImage.PreviewImage.Asset;
				}
			}
		}

		// if we have no asset until now, we could try to check if the target itself has a preview image.
		if (articyAsset == null)
		{
			var objectWithPreviewImage = aObject as IObjectWithPreviewImage;
			if (objectWithPreviewImage != null)
			{
				articyAsset = objectWithPreviewImage.PreviewImage.Asset;
			}
		}

		// and if we have an asset at this point, we load it as a sprite and show it in our ui image.
		if (articyAsset != null)
		{
			previewImagePanel.sprite = articyAsset.LoadAssetAsSprite();
		}
	}

	public void CopyTargetLabel(BaseEventData aData)
	{
		var pointerData = aData as PointerEventData;
		if (pointerData != null)
			GUIUtility.systemCopyBuffer = pointerData.pointerPress.GetComponent<Text>().text;
		Debug.LogFormat("Copied text \"{0}\" into clipboard!", GUIUtility.systemCopyBuffer);
	}
}